package com.groupbuying.redpacket.websocket;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.stereotype.Component;

import javax.websocket.*;
import javax.websocket.server.ServerEndpoint;
import java.io.IOException;
import java.util.concurrent.CopyOnWriteArraySet;

/**
 * @ClassName:  LargeScreenWebSocketServer
 * @Description: TODO   大屏页面websocket
 * @Author: srlg3
 * @Date: 2019/11/27
 */

@ServerEndpoint("/largeScreenWebsocket/{sid}")
@Component
public class LargeScreenWebSocketServer {
    public static final Logger LOGGER = LoggerFactory.getLogger(LargeScreenWebSocketServer.class);

    //静态变量，用来记录当前在线连接数。应该把它设计成线程安全的。
    private static int onlineCount = 0;

    //concurrent包的线程安全Set，用来存放每个客户端对应的MyWebSocket对象。
    private static CopyOnWriteArraySet<LargeScreenWebSocketServer> webSocketSet = new CopyOnWriteArraySet<LargeScreenWebSocketServer>();

   //与某个客户端的连接会话，需要通过它来给客户端发送数据
    private Session session;

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session) {
        this.session = session;
        if (onlineCount > 20){
            this.onClose();
            return;
        }
        //加入set中
        webSocketSet.add(this);
        //在线数加1
        addOnlineCount();
        LOGGER.error("有新窗口开始监听,当前在线人数为" + getOnlineCount());
        try {
            sendMessage("连接成功");
        } catch (IOException e) {
            LOGGER.error("websocket IO异常");
        }
    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose() {
        //从set中删除
        webSocketSet.remove(this);
        //在线数减1
        subOnlineCount();
        LOGGER.error("有一连接关闭！当前在线人数为" + getOnlineCount());
    }

    /**
     * 收到客户端消息后调用的方法
     *
     * @param message 客户端发送过来的消息
     */
    @OnMessage
    public void onMessage(String message, Session session) {
        LOGGER.info("收到来自窗口的信息:" + message);
        //群发消息
        for (LargeScreenWebSocketServer item : webSocketSet) {
            try {
                item.sendMessage(message);
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

    /**
     * @param session
     * @param error
     */
    @OnError
    public void onError(Session session, Throwable error) {
        LOGGER.error("发生错误");
        error.printStackTrace();
    }

    /**
     * 实现服务器主动推送
     */
    public void sendMessage(String message) throws IOException {
        this.session.getBasicRemote().sendText(message);
    }


    /**
     * 群发自定义消息
     */
    public static void sendInfo(String message){
        LOGGER.error("推送消息到窗口，推送内容:" + message);
        for (LargeScreenWebSocketServer item : webSocketSet) {
            try {
                //这里可以设定只推送给这个sid的，为null则全部推送
                item.sendMessage(message);
            } catch (IOException e) {
                continue;
            }
        }
    }

    public static synchronized int getOnlineCount() {
        return onlineCount;
    }

    public static synchronized void addOnlineCount() {
        LargeScreenWebSocketServer.onlineCount++;
    }

    public static synchronized void subOnlineCount() {
        LargeScreenWebSocketServer.onlineCount--;
    }
}
